Emulsion-treated wire mesh screens are commonly used with and without metal foils to screen print conductor patterns and conductive bonding substance patterns on the surfaces of ceramic and other substrates in the process of manufacturing electrical circuit devices. In the typical screen printing process, the screen is treated with an emulsion to render it impervious to the through-flow of the printing substance. The emulsion is dried and thereafter removed in preselected areas which correspond to the pattern to be printed. The screen is placed over the printing surface of the substrate and the printing substance is deposited onto the screen frame. An automatic or semiautomatic screen printing system is actuated to drive a flexible squeegee or the like across the screen thereby to push the printing substance through the areas of the screen which have been rendered pervious by emulsion removal. A very good quality print is obtainable using this method.
The typical printing operation is carried out on a substrate which is essentially free from major surface irregularities or protrusions. Under certain circumstances, however, it is desirable to perform a screen printing process after a device which is of substantial height as compared to the thickness of the printing screen has been bonded or otherwise secured to the printing surface of the substrate. Under these circumstances the printing screen cannot be placed flush against the printing surface and a satisfactory screen printing result cannot be obtained.